1. Field of the Invention
This invention relates to an electronic still camera, and in particular to a camera which is of a size capable of being held by the hand of the photographer and in which an optical image is converted into an electrical data and recorded.
2. Description of the Prior Art
In an electronic still camera of the hand held type an optical image formed on an image sensor is converted into electrical data and recorded, whereby an effect equivalent to that of the conventional still image recording using a photosensitive film is obtained. In a popular type of electronic still camera, use is made of a magnetic disc and when the magnetic disc is inserted into the camera, the magnetic disc comes into contact with a recording head and the electrical data put out from the head is recorded on the rapidly rotated magnetic disc.
The magnetic disc inserted into the camera remains in contact with the magnetic head until it is removed from the camera. Therefore, if the period of time from after photographing of a still image has been completed till the next photographing is long, there is an undesirable possibility that the tracks on the disc which are in contact with the magnetic head during that time are deformed. For example, in a system wherein there is a long wait with the head set to the next track to be photographed after completion of recording, there is a possibility that the track to be photographed is deformed by the contact between the magnetic head and the magnetic disc, and in a system wherein the magnetic head is moved to a fresh track immediately before recording is started, there is a possibility that the previously recorded track is deformed by long contact between the magnetic head and the magnetic disc.
Also, due to the fact that the magnetic head is in contact with a recorded track or a track to be recorded at a point of time whereat photographing is started, the contact resistance between the magnetic head in its stationary state and the magnetic disc is great when rotation of the magnetic disc is started, and this may injure the disc. Of course, all of this holds true not only of electronic still cameras, but also of apparatuses in which recording and reproduction are effected with the head brought into contact with the magnetic disc.
In the electronic still camera shown in Japanese Laid-open Patent Application No. 140506/1979, there is provided a mechanism for retracting the magnetic head from the surface of the magnetic disc to prevent the magnetic head and the magnetic disc from being injured during the mounting or dismounting of the magnetic disc with respect to the camera and to permit smooth mounting or dismounting of the disc with respect to the camera, but this retracting mechanism works during the mounting or dismounting of the magnetic disc and requires a complex mechanism to retract the magnetic head until the magnetic disc reaches its steady rotation during each photographing, and this leads to bulkiness of the camera. For this reason, such mechanism has not been used in practice.